1. Field of the Invention
The present invention related to a recording head in which a head portion for recording an image and a sensor portion for reading the image recorded by the head portion are placed on one base member to form a head module.
2. Description of the Related Art
For example, a type of ink jet printer is known which records an image by using a line head capable of recording one image line on a recording medium (the line corresponding to the length of one side of the recording medium) at a time, and by moving the recording medium relative to the line head in a transport direction perpendicular to the direction of arrangement of the recording elements of the line head. Printers using a line head use a plurality of head components, and a method of increasing the printing width by placing the head components in a staggered structure is also known.
Each of the head components is constructed by arranging, in one direction, nozzles (recording elements) for forming an image on a recording medium by ejecting ink. In the staggered structure, the plurality of head components are staggered (alternately placed) between two rows along the direction of arrangement of its recording elements. Two head components placed in the different rows and located adjacent to each other along the direction of arrangement of the recording elements are placed so that a pitch between the recording elements at ends of two head components is equal to a pitch between the other recording elements which are not at the ends of two components.
In a printer using a line head of such a staggered structure, it is important to consider the accuracy of adjusting a position of the head components at their joints (gaps) from the viewpoint of recording a high-quality image free from a stripe shape density nonuniformity, a blank defect, and the like. However, the recording elements are arranged at extremely short intervals (e.g., with a pitch of about 21 xcexcm in the case of 1200 dpi). It is considerably difficult to accurately adjust the position of the head components and to place a number of head components in a staggered structure.
In view of the above-described problem of the conventional art, an object of the present invention is to provide a recording head which is constructed as a line head by arranging a plurality of head components along the direction of arrangement of recording elements, and in which an amount of gap of the recording elements at each of the joints between each pair of the head components located adjacent to each other along the direction of arrangement of the recording elements is detected to achieve recording of a high-quality image free from a stripe shape nonuniformity, a blank defect and a color nonuniformity.
In order to attain the object described above, the present invention provides a recording head comprising: a head portion for recording an image on a recording medium, the head portion having at least one row of short head components, each row of short head components being constructed by arranging a plurality of short head components in one direction, each of the plurality of short head components having at least one row of recording elements, each row of recording elements being constructed by arranging a plurality of recording elements in the one direction; a sensor portion for reading the image recorded on the recording medium by the head portion, the sensor portion having at least one row of reading elements, each row of reading elements being constructed by arranging in the one direction a plurality of reading elements for reading the image recorded on the recording medium; and one base member on which the head portion and the sensor portion are placed while being fixedly positioned relative to each other to integrally form a head module.
Preferably, the head portion records a monochrome image on the recording medium, the at least one row of short head components in the head portion is a row of short head components, the at least one row of recording elements in each of the short head components is a row of recording elements for recording the monochrome image on the recording medium, the row of recording elements corresponding to monochrome in the monochrome image, and the at least one row of reading elements in the sensor portion is a row of reading elements for reading the monochrome image recorded on the recording medium.
Preferably, the head portion records a multicolor image on the recording medium, the at least one row of short head components in the head portion is a row of short head components being constructed by placing the plurality of short head components along the direction; and the at least one row of recording elements in one of the short head components is a plurality of rows of recording elements for recording the multicolor image on the recording medium, each of the plurality of rows of recording elements corresponding to each of a plurality of colors in the multicolor image.
Preferably, the sensor portion reads the multicolor image recorded on the recording medium by the head portion, and the at least one row of reading elements in the sensor portion is a row of reading elements for reading the multicolor image recorded on the recording medium.
Preferably, each of the plurality of reading elements is a reading element for monochrome.
Preferably, the plurality of reading elements are reading elements for reading the multicolor image recorded on the recording medium, the reading elements corresponding to respective colors in the multicolor image.
Preferably, the sensor portion reads the multicolor image recorded on the recording medium by the head portion, and the at least one row of reading elements in the sensor portion is a plurality of rows of reading elements for reading the multicolor image recorded on the recording medium, each of the plurality of rows of reading elements corresponding to each of a plurality of colors in the multicolor image.
Preferably, the head portion records a multicolor image on the recording medium, the at least one row of short head components in the head portion is a plurality of rows of short head components for recording the multicolor image on the recording medium, each of the plurality of rows of short head components corresponding to each of a plurality of colors in the multicolor image, and the at least one row of recording elements in each of rows of short head components is a row of recording elements.
Preferably, the sensor portion reads the multicolor image recorded on the recording medium by the head portion, and the at least one row of reading elements in the sensor portion is a row of reading elements for reading the multicolor image recorded on the recording medium.
Preferably, each of the plurality of reading elements is a reading element for monochrome.
Preferably, the plurality of reading elements are reading elements for reading the multicolor image recorded on the recording medium, the reading elements corresponding to respective colors in the multicolor image.
Preferably, the sensor portion reads the multicolor image recorded on the recording medium by the head portion, the at least one row of reading elements in the sensor portion is a plurality of rows of reading elements for reading the multicolor image recorded on the recording medium, each of the plurality of rows of reading elements corresponding to each of a plurality of colors in the multicolor image.
Preferably, the plurality of rows of short head components comprises respective rows of short head components corresponding to respective colors of the plurality of colors, one row of short head components for one color being constructed by arranging in the one direction the plurality of short head components adjacent to each other in a direction perpendicular to the one direction.
Preferably, the plurality of rows of short head components are constructed by arranging in the one direction a plurality of groups of short head components, each of the plurality of groups of short head components having the plurality of short head components arranged in a direction perpendicular to the one direction, each of the plurality of short head components corresponding to each of the plurality of colors.
Preferably, each of the plurality of short head components in the plurality of rows of short head components is placed as that positions of joints between the short head components in each of the plurality of rows of short head components corresponding to each of the plurality of colors are shifted.
Preferably, the sensor portion is constituted of a plurality of sensor components placed along the one direction; each of the plurality of sensor components is constructed by arranging a certain number of reading elements among the plurality of reading elements along the one direction; and a position of a recording element at one end of each of the plurality of short head components is positioned inside from the reading elements at both ends of each of the sensor components which corresponds to the recording elements at one end of each of the plurality of short head components among the plurality of sensor components.
Preferably, the sensor portion has a plurality of the reading elements placed at least a region corresponding to a predetermined number of the recording elements at both sides of the one direction from a recording element at one end of each of the plurality of short head components.
Preferably, the predetermined number of the recording elements are at least five.
Preferably, the short head components in each of the plurality of rows of short head components are placed at least in two rows along the one direction, and any two of the short head components located adjacent to each other along the one direction are placed in the different rows and placed so as to overlap at least one recording element; and the sensor portion has a plurality of reading elements placed at least a region corresponding to a region of overlapping any two of the short head components located adjacent to each other along the one direction.
To attain the object described above, according to one aspect of the present invention, there is provided a recording head comprising: a head portion for recording an image on a recording medium, the head portion being constructed of a plurality of short head components, each of which has at least one row of recording elements arranged in one direction and which are arranged along the one direction of arrangement of the recording elements; a sensor portion for reading the image recorded on the recording medium by the head portion, the sensor portion being constructed by arranging in the one direction a plurality of reading elements for reading the image recorded on the recording medium; and one base member on which the head portion and the sensor portion are placed while being fixedly positioned relative to each other to integrally form a head module.
According to the other aspect of the present invention, there is provided a recording head comprising: a head portion for recording a multicolor image on a recording medium, the head portion being constructed by placing a plurality of short head components along one direction; a sensor portion for reading the multicolor image recorded on the recording medium by the head portion, the sensor portion being constructed by arranging in the one direction a plurality of reading elements for reading the multicolor image recorded on the recording medium; and one base member on which the head portion and the sensor portion being placed while being fixedly positioned relative to each other to integrally form a head module; wherein each of the short head components has a plurality of groups of recording elements for recording the multicolor image on the recording medium, each group of the plurality of groups of recording elements corresponding to each color of a plurality of colors, a plurality of recording elements in the each group being arranged along the one direction of arrangement of the short head components.
According to the other aspect of the present invention, there is provided a recording head comprising: a head portion for recording a multicolor image on a recording medium, the head portion having a plurality of groups of short head components for recording a multicolor image on the recording medium, each group of the plurality of groups of short head components corresponding to each color of a plurality of colors, a plurality of short head components in the each group being arranged in one direction, each of the plurality of short head components in the each group corresponding to the each color having a plurality of recording elements corresponding to the each color, the plurality of recording elements being arranged along the one direction of arrangement of the short head components; a sensor portion for reading the multicolor image recorded on the recording medium by the head portion, the sensor portion being constructed by arranging in the one direction a plurality of reading elements for reading the multicolor image recorded on the recording medium; and one base member on which the head portion and the sensor portion are placed while being fixedly positioned relative to each other to integrally form a head module.
According to the other aspect of the present invention, there is provided a recording head comprising: a head portion for recording a multicolor image on a recording medium, the head portion having a plurality of groups of short head components for recording a multicolor image on the recording medium, each group of the plurality of groups of short head components corresponding to each color of a plurality of colors, a plurality of short head components in the each group being arranged in one direction, each of the plurality of short head components in the each group corresponding to the each color having a plurality of recording elements corresponding to the each color, the plurality of recording elements being arranged along the one direction of arrangement of the short head components; a sensor portion for reading the multicolor image recorded on the recording medium by the head portion, the sensor portion having a plurality of groups of reading elements for reading the multicolor image recorded on the recording medium, each group of the plurality of groups of reading elements corresponding to each color of a plurality of colors, a plurality of reading elements in the each group being arranged in the one direction; and one base member on which the head portion and the sensor portion are placed while being fixedly positioned relative to each other to integrally form a head module.
Preferably, the each of the short head components is placed as that positions of joints between the short head components in the each group corresponding to the each color are shifted.
Preferably, the sensor portion is constituted of a plurality of sensor components placed along the one direction of arrangement of the reading elements; each of the sensor components is constructed by arranging a certain number of reading elements out of the plurality of reading elements along the one direction of arrangement of the reading elements; and a position of each of the recording elements at both ends of each of the short head components is spaced apart from the reading elements at both ends of each of the sensor components in a direction toward an intermediate point of the one direction of arrangement of reading elements of corresponding the sensor component.
Preferably, the sensor portion has a plurality of the reading elements placed at least a reading element region corresponding to a region of a predetermined number of the recording elements at both sides of the one direction of arrangement of the recording elements from the recording elements at both ends of each of the short head components.
Preferably, the predetermined number of the recording elements are at least five.
Preferably, the short head components are placed at least in two rows along the one direction of arrangement of the recording elements, and any two of the short head components located adjacent to each other along the one direction of arrangement of the recording elements are placed in the different rows and placed so as to overlap at least one recording element; and the sensor portion has a plurality of the reading elements placed at least a reading element region corresponding to a region of overlapping any two of the short head components located adjacent to each other along the one direction of arrangement of the recording elements.